Elemental Debate

Even before detente, Russian and American scientists were trading views, visits and even data. But the cordial atmosphere is occasionally clouded by acrimony. Last week, for the third time in a decade, the scientific cold war between the University of California's Lawrence Berkeley Laboratory and the Soviet Union's Joint Institute for Nuclear Research at Dubna, near Moscow, erupted anew. As before, the argument was over who had been first to manufacture the latest manmade* element.

The synthesis of element No. 106 was announced last week by a Berkeley team led by Physicist Albert Ghiorso and Chemist Glenn Seaborg, the former Atomic Energy Commission chairman who won a Nobel Prize for synthesizing element No. 94 (plutonium). The Berkeley scientists used a newly beefed-up particle accelerator called Super-HILAC (for heavy ion linear accelerator) to send nuclei of oxygen atoms barreling into another artificial element, californium. As occasional collisions occurred between the oxygen and californium nuclei, they fused and formed the heavier nucleus of element 106--but not for long. Like most artificial elements, No. 106 is extremely unstable. It has a half-life of only nine-tenths of a second--that is, half of its atoms will break apart into simpler atoms in that brief span of time. Thus the substance quickly decayed into lighter elements.

Shaky Ground. The Russians, led by Physicist Georgy N. Flerov, last June claimed a similar achievement using another technique: firing nuclei of chromium into lead. That produced a slightly different isotope of element 106 with an even shorter half-life of less than one-hundredth of a second. The Berkeley group was highly skeptical. Said Ghiorso: "The proof they presented is marginal. I think they are on shaky ground."

It will be up to the already burdened International Union of Pure and Applied Chemistry to settle the issue. The union still has not determined who first made elements 104 and 105, for which each side has filed claims and names. The Russians are calling 104 "kurchatovium" (after their A-bomb pioneer, Igor Kurchatov) and 105 "niels bohrium" (for the famed Danish physicist). Americans have dubbed 104 "rutherfordium" (after the English scientist Ernest Rutherford) and 105 "hahnian" (for German Chemist Otto Hahn, who discovered nuclear fission).

In the case of element 106, both sides have agreed on at least one thing: to hold off on any names until the international union decides who was first.

* As opposed to the 92 natural elements, which range in complexity from hydrogen--with one proton in its nucleus--to uranium, with 92.

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